--- a/networking/udhcp/packet.c
+++ b/networking/udhcp/packet.c
-@@ -120,6 +120,10 @@ uint16_t FAST_FUNC udhcp_checksum(void *
+@@ -158,6 +158,11 @@ uint16_t FAST_FUNC udhcp_checksum(void *
return ~sum;
}
-+int udhcp_get_payload_len(struct dhcpMessage *payload)
++int udhcp_get_payload_len(struct dhcp_packet *dhcp_pkt)
+{
-+ return sizeof(struct dhcpMessage) - DHCP_OPTIONS_BUFSIZE + end_option(payload->options) + sizeof(payload->options[0]);
++ return sizeof(struct dhcp_packet) - DHCP_OPTIONS_BUFSIZE + udhcp_end_option(dhcp_pkt->options) + sizeof(dhcp_pkt->options[0]);
+}
-
++
/* Construct a ip/udp header for a packet, send packet */
- int FAST_FUNC udhcp_send_raw_packet(struct dhcpMessage *payload,
-@@ -132,11 +136,7 @@ int FAST_FUNC udhcp_send_raw_packet(stru
+ int FAST_FUNC udhcp_send_raw_packet(struct dhcp_packet *dhcp_pkt,
+ uint32_t source_nip, int source_port,
+@@ -166,10 +171,10 @@ int FAST_FUNC udhcp_send_raw_packet(stru
+ {
+ struct sockaddr_ll dest_sll;
+ struct ip_udp_dhcp_packet packet;
+- unsigned padding;
int fd;
int result = -1;
const char *msg;
--
-- enum {
-- IP_UPD_DHCP_SIZE = sizeof(struct udp_dhcp_packet) - CONFIG_UDHCPC_SLACK_FOR_BUGGY_SERVERS,
-- UPD_DHCP_SIZE = IP_UPD_DHCP_SIZE - offsetof(struct udp_dhcp_packet, udp),
-- };
-+ int p_len = udhcp_get_payload_len(payload);
++ int p_len = udhcp_get_payload_len(dhcp_pkt);
fd = socket(PF_PACKET, SOCK_DGRAM, htons(ETH_P_IP));
if (fd < 0) {
-@@ -146,7 +146,7 @@ int FAST_FUNC udhcp_send_raw_packet(stru
+@@ -178,8 +183,8 @@ int FAST_FUNC udhcp_send_raw_packet(stru
+ }
- memset(&dest, 0, sizeof(dest));
- memset(&packet, 0, sizeof(packet));
-- packet.data = *payload; /* struct copy */
-+ memcpy(&(packet.data), payload, p_len);
+ memset(&dest_sll, 0, sizeof(dest_sll));
+- memset(&packet, 0, offsetof(struct ip_udp_dhcp_packet, data));
+- packet.data = *dhcp_pkt; /* struct copy */
++ memset(&packet, 0, sizeof(packet));
++ memcpy(&(packet.data), dhcp_pkt, p_len);
- dest.sll_family = AF_PACKET;
- dest.sll_protocol = htons(ETH_P_IP);
-@@ -163,23 +163,18 @@ int FAST_FUNC udhcp_send_raw_packet(stru
- packet.ip.daddr = dest_ip;
+ dest_sll.sll_family = AF_PACKET;
+ dest_sll.sll_protocol = htons(ETH_P_IP);
+@@ -192,36 +197,24 @@ int FAST_FUNC udhcp_send_raw_packet(stru
+ goto ret_close;
+ }
+
+- /* We were sending full-sized DHCP packets (zero padded),
+- * but some badly configured servers were seen dropping them.
+- * Apparently they drop all DHCP packets >576 *ethernet* octets big,
+- * whereas they may only drop packets >576 *IP* octets big
+- * (which for typical Ethernet II means 590 octets: 6+6+2 + 576).
+- *
+- * In order to work with those buggy servers,
+- * we truncate packets after end option byte.
+- */
+- padding = DHCP_OPTIONS_BUFSIZE - 1 - udhcp_end_option(packet.data.options);
+-
+ packet.ip.protocol = IPPROTO_UDP;
+ packet.ip.saddr = source_nip;
+ packet.ip.daddr = dest_nip;
packet.udp.source = htons(source_port);
packet.udp.dest = htons(dest_port);
- /* size, excluding IP header: */
-- packet.udp.len = htons(UPD_DHCP_SIZE);
+- packet.udp.len = htons(UDP_DHCP_SIZE - padding);
- /* for UDP checksumming, ip.len is set to UDP packet len */
+ p_len += sizeof(packet.udp);
+ packet.udp.len = htons(p_len);
packet.ip.tot_len = packet.udp.len;
-- packet.udp.check = udhcp_checksum(&packet, IP_UPD_DHCP_SIZE);
+- packet.udp.check = udhcp_checksum(&packet, IP_UDP_DHCP_SIZE - padding);
- /* but for sending, it is set to IP packet len */
-- packet.ip.tot_len = htons(IP_UPD_DHCP_SIZE);
+- packet.ip.tot_len = htons(IP_UDP_DHCP_SIZE - padding);
+ p_len += sizeof(packet.ip);
+ packet.udp.check = udhcp_checksum(&packet, p_len);
+ packet.ip.tot_len = htons(p_len);
packet.ip.ttl = IPDEFTTL;
packet.ip.check = udhcp_checksum(&packet.ip, sizeof(packet.ip));
-- /* Currently we send full-sized DHCP packets (zero padded).
-- * If you need to change this: last byte of the packet is
-- * packet.data.options[end_option(packet.data.options)]
-- */
-- result = sendto(fd, &packet, IP_UPD_DHCP_SIZE, 0,
-+ result = sendto(fd, &packet, p_len, 0,
- (struct sockaddr *) &dest, sizeof(dest));
+ udhcp_dump_packet(dhcp_pkt);
+- result = sendto(fd, &packet, IP_UDP_DHCP_SIZE - padding, /*flags:*/ 0,
++ result = sendto(fd, &packet, p_len, /*flags:*/ 0,
+ (struct sockaddr *) &dest_sll, sizeof(dest_sll));
msg = "sendto";
ret_close:
-@@ -231,8 +226,7 @@ int FAST_FUNC udhcp_send_kernel_packet(s
- goto ret_close;
+@@ -239,7 +232,6 @@ int FAST_FUNC udhcp_send_kernel_packet(s
+ uint32_t dest_nip, int dest_port)
+ {
+ struct sockaddr_in client;
+- unsigned padding;
+ int fd;
+ int result = -1;
+ const char *msg;
+@@ -270,9 +262,7 @@ int FAST_FUNC udhcp_send_kernel_packet(s
}
-- /* Currently we send full-sized DHCP packets (see above) */
-- result = safe_write(fd, payload, DHCP_SIZE);
-+ result = safe_write(fd, payload, udhcp_get_payload_len(payload));
+ udhcp_dump_packet(dhcp_pkt);
+-
+- padding = DHCP_OPTIONS_BUFSIZE - 1 - udhcp_end_option(dhcp_pkt->options);
+- result = safe_write(fd, dhcp_pkt, DHCP_SIZE - padding);
++ result = safe_write(fd, dhcp_pkt, udhcp_get_payload_len(dhcp_pkt));
msg = "write";
ret_close:
close(fd);
projects / openwrt.git / blobdiff